Sewing machine work-holding attachment for darning and embroidering



Dec. 25, 1951 R. E. JOHNSON SEWING MACHINE WORK-HOLDING ATTACHMENT FOR DARNING AND EMBROIDERING 2 Sl-IEETS -SI-IEET 1 Filed Jail. 15, 1948 v gwue nkm/ Ralph E. Johnson attorney Wan 7?? Dec. 25, 1951 R. E. JOHNSON 2,580,101

SEWING MACHINE WORK-HOLDING ATTACl-IMENT FOR DARNING AND EMBROIDERING Filed Jan. 15, 1948 2 SHEETS-Sl-IEET 29 3? 519 30 K W E J? I 51 W azis S M/mambo? W'LrYLG/b= 4 wgalph E. Johnson Patented Dec. 25, 1951 SEWING MACHINE WORK-HOLDING AT- TACHMENT FOR EARNING EM- BROIDERING Ralph E. Johnson, Rahway, N. J assignor to The Singer Manufacturing Company,

Elizabeth,

N. J., a corporation of New Jersey I Application January 15, 1948, Serial No. 2,456

Claims.

This invention relates to darning attachments for use with sewing machines, and more particularly to an attachment for holding the work suitably for darning and to facilitate maneuvering the work beneath the sewing needle.

Securing the work preparatory to performing darning operations thereupon may be accomplished by the use of nested clamping rings or darning hoops. To assist in disposing one clamping ring against the under surface of the work,

. the sewing machine, however, ordinarily results in restricting the freedom of movement of the ring and, consequently, the freedom of move ment of the work clamped thereby. It is one object of this invention to provide a work-clamping attachment which may be mounted on the bed of a sewing machine, but which nevertheless possesses complete freedom of movement within defined'limits. More specifically, this invention includes a new construction for a darning attachment or the like in which at least one of the clamping elements is mounted on the bed of the machine to simplify positioning and clamping the work, but which may be freely shifted beneath the needle to facilitate the execution of darns of any desired pattern.

It is a further object of this invention to provide work-clamping elements which may be easily engaged and disengaged, and which tension and position the work suitably for darning.

The invention also provides a work-clamping element having an annular gripping surface by means of which the operator may manipulate the attachment without touching the fabric. This is particularly effective in preventing soiling of the work and inadvertent interference with the tensioning thereof.

A detailed description of one embodiment of the invention, from whichthese and other advantages will be more clearly understood, follows in the specification referring to the drawings, in which:

Fig. 1 is a side elevational view of a portion showing in cutaway section the means for mounting the attachment thereupon.

Fig. 2 is a top plan view of the cylindrical bed of the sewing machine, including the mounted darning attachment, and with the needle and presser-bars sectioned along the line 2--2 of Fig. 1. Shown in broken lines are four of the extreme operating positions into which the darning attachment may be shifted.

Fig. 3 is an enlarged sectional view of the darning attachment taken substantially along the line 33 of Fig. 2 with the addition of a piece of work shown secured by the clamping elements.

Fig. 4 is an exploded perspective View of the component elements of the darning attachment.

The sewing machine, a portion of which is shown in the accompanying drawingsis of the cylinder-bed type having an eye-pointed needle 1 0 carried by a reciprocating needle-bar H. The sewing machine is provided with a substantially cylindrical bed-portion [2 having a flattened upper or working surface and housing a feed-dog l3 along with the usual feed-dog actuating and loop-seizing mechanism. A detailed illustration of such a machine may be observed by reference to U. S. Patent No. 2,386,660 of A. B. Clayton. v

Also contained within the bed is a mechanism for lowering the feed-dog beneath the plane of the throat-plate M to prevent its interference with the freedom of movement of the work required in performing darning operations. A typical device of this type is shown in the U. S. Patent No. 1,908,292 of A Grieb.

A darning presser-foot I5 is secured to a presser-bar It. In order to provide for freedom l of movement of the work, it is also helpful to the pin'maybe anchored in the bed of the sewing machine. This is accomplished by introduccyclically raise the presser-foot from engagement therewith. This temporary disengagement occurs once in each stitch-forming cycle immediately following the time of seizure of the needlethread by the loop-taker, and may be accomplished by any one of several commonly used devices, one of which is shown in the U. S. Patent No. 2,009,194 of P. Hleb.

The darning attachment comprises an annu lar bearing ring or supporting element I! (Fig. 4) carried by. one end of a supporting arm or element [8 provided with a longitudinal slot I9. A mounting pin 20, slidably but non-rotatably mounted in the slot [9, is provided on its depending end with a head or lug- 2| by means of which ing the rectangular lug 2| into a correspondingly shaped slot 22 in a bed-plate 23. The lug underlies the under surface of the bed-plate thus permitting the pin to pivot about its cylindrical shank portion 24. In the normal operating pobearing ring ll.

sitions of the attachment the long axis of the lug 2I is disposed transversely to that of the slot 22, thus preventing accidental withdrawal of the pin.

A clamping element provided with a split 25, and having as its cross-section an outwardly opening channel including a cylindrical wall in the form of a ring 26 and circumferential flanges 21 and 32, is sprung within the bearing ring IT. The bearing ring l1, its supporting arm l8, and the split clamping element 25 form a unitary structure, the respective components of which are not separable in normal use. It is to be noted, however, that the clamping element 25 may be rotated relatively to the bearing ring l'l.

A second clamping element 28 cooperates with the. clamping element 25 to secure the work W, as illustrated in Fig. 3. The clamping element 28 is comprised of an annular shelf or flange 29 from which depend the concentric cylindrical rings 30 and 3!. ments are in engagement, these cylindrical rings embrace the iiange 2] of the element 25.

To operate the device the work is placed over the clamping element 25 with the damaged fibers dis-posed centrally thereof, and the clamping element 28 is pressed downwardly onto the element The latter is forced to yield radially inwardly by the rigid outer cylindrical ring 39 of the clamping element 2.8. and the work is consequently gripped between the outer edge of the upper horizontal flange '21 and the inner face of the cylindrical ring 5.5!. The inner ring 3| is wider than the outer ring 53 so that in work-clamping position, the lower rim of the ring 3! is approximately at the level of the lower face of thesupporting arm l8, thereby causing the work to be disposed substantially in the plane of the throatplate I4. As the clamping elements are pressed into engagement, the inner ring 3! of the element 2ii'causes the work-to be drawn taut by an amount proportional to the clamping force of the aforementioned clam-ping surfaces. This clamping force is supplemented by the snubbing action .of the fabric about the lower edges of the cylindrical rings .30 and 3|, as well as about the inner edge of the flange 21.

In engaging the clamping elements, the cylindrical ring 3| of the clamping element 28 fits loosely within the element 25 and acts as a piloting or positioning member which centers the clamping elements prior to the time that they are pressed into engagement. It should also be noted that the horizontal shelf 29 of the clamping element 28 overlies the element 25 and thus forms a surface .by means of which the attachment may be held by the operator in maneuvering the work beneath the needle.

The pair of engaged clampin elements 25 and 28 may be rotated as a unit relatively to the The bearing ring IT, on the other hand, may be turned about the pivot pin 29, and in addition, may be shifted linearly within the limits def ned by the len th of the slot I9 in the supporting arm l8 This combination of motions available to the work clamping elements enables the work secured thereby to be shifted with complete freedom in a horizontal plane within the defined limits.

Having described in detail an apparatus considered to represent a typical embodiment of the invention, what claimed is:

l. A-work-holding device of the class described comprising: a first clamping element, a second When the clamping eleclamping element including a pair of concentric cylindrical rings, and a shelf joining said cylindrical rings, said clamping elements being adaptable to be pressed into concentric engagement in which the first clamping element is disposed radially Within the concentric rings of the second clamping element.

2. A work-holding device of the class described comprising: a first clamping element including a cylindrical ring, and a flange extending outwardlytherefrom, a second clamping element including a pair of concentrically disposed cylindrical rings, and a shelf joining the rings, saidfirst and second clamping elements being adaptable to be pressed into substantially concentric engagement in which the first clamping element is disposed within the radial confines of the pair of cylindrical rings of the said second clamping element.

3. A work-holding device or the class described comprising: a first annular clamping element the cross-section of which is an outwardly opening channel, a second annular clamping element the cross-section of which is a downwardly opening channel, said clamping elements being adapted to be pressed into confentric engagement in which the first clamping element is at least partially disposed within the channel of the second clamping element.

4. A work-holding device for use with a sewing machine comprising: a first annular clamping element the cross-section of which is an outwardly opening channel, a second annular workclam-p-ing element the crossesection of which'is a downwardly opening channel, said second clamping element being adaptable to engage said first clamping element, an annular supporting element journaled within the channel of the said first clamping element, said clamping elements being rotatable relatively to said supporting element, and a supporting arm carrying said supporting element adaptable to be removably mounted on a sewing machine.

5. A work-holding device for use with a sewing machine comprising: a first annular clamping element the cross-section of which is an outwardly opening channel, a second annular workclamping eienient the cross-section of which is a downwardly opening channel, said second clam-ping element being adaptable to engage said first clamping element, an annular supporting ring journaled within the channel of the first clamping. element, said clamping elements being rotatable relatively to said supporting ring, a slotted supporting arm .affiXed to said supporting ring, and a pin slidably mounted in'said slotted supporting arm by means of which the device may be mounted upon a sewing machine.

RALPH JOHNSON.

REFERENCES CITED The following references areof record in the file of this patent:

UNITED STATES PATENTS Number Name Date 986,692 Collier Mar. 14, 1911 1,098,442 Huyck June 2, 1914 2,471,370 Gegauf May 24, 1949 Q EI ATE TS Number Country Date 641,607 France Apr. 21,1928 

